30 Stocks Traders Are Shorting Like Crazy

Short sellers, or investors betting that the price of a stock will go down, have to overcome unexpected fees, as well as simple math: you can only ever make 100% on a short position, but your losses are potentially infinite.

And just this morning, SodaStream, a stock that is heavily shorted, saw shares pop after Bloomberg reported the company was in talks to go private.

But this doesn't stop traders from taking their best shot.

Year-to-date, all of the major stock indexes are higher, with the Nasdaq gaining more than 7.5% and the benchmark S&P 500 adding 7%. Despite these broad gains, we've found 30 stocks with market caps larger than $2 billion that people are betting against like crazy.

On the list, of course, is Herbalife, the company that hedge funder Bill Ackman has accused of being a pyramid scheme.

Other high-profile companies on the list include electric carmaker Tesla and yoga apparel maker lululemon.

This list, however, also exhibits two major themes: China and solar energy.

We ranked the stock by short interest as a percentage of shares outstanding, going from the least shorted to the most.

Tesla Motors

Comment: Tesla CEO Elon Musk recently announced that the company would make its patents availabe for free use, saying the company's competitors were not other electric carmakers but any company making a car that runs on gasoline.

Ubiquiti Networks

Questcor

Mallinckrodt

Ticker: QCOR

Short interest: 30%

YTD return: 78.3%

Sector: Pharmaceuticals

Comment: In April, Questcor and Mallinckrodt announced an agreement to merge in a deal expected to close during the third quarter. The New York Times noted, however, there are pretty big risks associated with Questcor's Achtar immune-system drug.

SolarCity

AP

Ticker: SCTY

Short interest: 32.5%

YTD return: 26.5%

Sector: Renewable Energy

Comment: In June, SolarCity announced plans to build one of the world's largest solar plants in upstate New York. The company's chairman is Elon Musk, the CEO of Tesla, another company that appears on this list.

data from FinViz

Lululemon

Comment: The yoga apparel company's founder, Chip Wilson, who stepped down as chairman of the board in December, is working with Goldman Sachs to get control of the company back. Wilson is Lululemon's largest shareholder.

data from FinViz

Amtrust Financial Systems

Amtrust Financial

Ticker: AFSI

Short interest: 39.7%

YTD return: 25.8%

Sector: Insurance

Comment: Amtrust Financial has increased gross written insurance premiums 36% each year over the past five, but some have begun to wonder if the company can sustain its growth.

data from FinViz

Zulily

Business Insider / Jillian D'Onfro

Ticker: ZU

Short interest: 50.4%

YTD return: -12.6%

Sector: Online Retail

Comment: Zulily is a daily deals site for moms, and we recently toured its Seattle offices. In May, the company reported sales that grew 87% in the first quarter and raised its fiscal-year revenue expectations.